1. Field of the Invention
The present invention relates to fabrication of semiconductor memory devices, in particular to a method of fabricating a crown-shaped capacitor for semiconductor memory devices.
2. Description of the Related Art
A dynamic random access memory (DRAM) device is a kind of a volatile memory device. Digital data storage in a DRAM device is executed by charges and discharges of a capacitor in the DRAM device. When power supplied to the DRAM device is turned off, the data stored in the memory cell of the DRAM device completely disappears. A memory cell in the DRAM device typically includes at least one field effect transistor (FET) and one capacitor. The capacitor is used for storing signals in the cells of the DRAM device. Commonly used capacitors today, are trench capacitors and crown-shaped capacitors.
With the size of DRAM device memory cells shrinking, the technological development to maintain the appropriate charge capacitance of capacitors has fallen behind that of the technological development to shrink memory cells. Namely, as the size of the capacitor in a memory cell is reduced, a predetermined charge capacitance is still required for reliable storage of signals.
Thus, methods for fabricating smaller capacitors, capable of maintaining or increasing storage capacitance, are desired.